Network cameras are known in the related art which are controlled by remote control through a network or an exclusive line to monitor a predetermined monitoring area. Some of such network cameras include a driving unit for panning (rotating in a horizontal direction) and tilting (rotating in a vertical direction) an image capturing unit for capturing an image of a subject to move the image capture direction.
Network cameras are operated in accordance with commands transmitted from an external device connected over a network. Users transmit a driving command for a rightward or leftward panning motion, an upward or downward tilting motion, or a panning and tilting motion, which is a combination thereof, to the network camera by operating the external device.
This allows the users to move the image capturing unit of the network camera in a desired rotational direction and to stop the image capturing unit at a given position by transmitting a stop command while viewing an image during movement. In this way, the users operate the network camera in a desired image capture direction, thereby capturing an image of a target area.
PTL 1 discloses an image capturing apparatus in which the image capture direction can be changed by operating a pan head by key operation on a mobile phone having a browser function or a mouse operation on a personal computer.
However, with the related art disclosed in PTL 1, it is sometimes difficult to move the image capture direction of the network camera by a minute amount.
In general, a time delay occurs between the time a network camera receives a driving command for a panning and tilting motion of an image capturing unit and the time an image capturing unit actually starts to operate due to a waiting time in control processing, the characteristics of a power transmission system of the image capturing unit, and so on.
For example, assume a case in which an image capturing unit is moved by a minute amount for fine adjustment of the image capturing direction of a network camera. Under such assumption, the user transmits a stop command for stopping a panning or tilting motion of the image capturing unit to the network camera immediately after transmitting a driving command for the panning and tilting motion without a time difference.
At that time, the driving command is sometimes cancelled because the stop command received during the time delay between the time the network camera receives the driving command and the time the image capturing unit actually starts to operate is executed. Thus, the image capturing unit of the network camera sometimes terminates the process without starting operation.
In the case where the stop command is transmitted after the driving command is transmitted and the user visually confirms that the image capturing unit has started to operate, the stop timing of the image capturing unit is sometimes delayed due to the time delay between the execution times of the individual commands. Because of this, the stop position of the image capturing unit sometimes passes through a user's intended position.